About thermal admittance and difusivity
Fragment of a discussion from Course talk:APBI200/Archive/2016-17WT2
Steven, thermal diffusivity (slides 21-22 of lecture #12) is driven in part by thermal conductivity (which increases exponentially in mineral soils with a small amount of soil moisture - see slide 15). Consider 2 soils (1 mineral and 1 organic) both of which are subject to a 1 degree increase in soil temperature - the mineral soil will rapidly conduct heat downwards due to it's high thermal conductivity. While it takes more energy to warm a "wet" mineral soil, once the temperature increases, that heat will be conducted down.
SandraBrown (talk)